Koji Watanabe began illustrating Duel Masters cards for Wizards of the Coast during production of the Stomp-a-Trons of Invincible Wrath set, for which Koji illustrated Tentacle Worm.

You can look up Tentacle Worm, along with every other Duel Masters card printed in English, in the Duel Masters card database, here: http://www.wizards.com/duelmasters/dmdb.asp Note that the database does not show promotional cards.